Centrifugal pump



E. J. PURCELL ETAL Oct. 21, 1958 CENTRIFUGAL PUMP Filed July 13, 1953 2Sheets-Sheet 1 INVENTORS EDWARD .J.PURCELL DUDLEY W- FLAGLER GEORGEL.HARVILLE Oct. 21, 1958 E. J. PURCELL ETAL 2,856,858

'CENTRIFUGAL PUMP 2 Sheets-Sheet 2 Filed July 15, 1953 FIG.3

FIGA

INVENTORS EDWARD J. PURCELL DUDLEY W. FLAGLER GEORGE L.HARVILLE m MM ATTORNEY base.

left, or upward, or at an angle.

United States Patent CENTRIFUGAL PUMP Edward J. Purcell, Dudley W.Flagler, and George L. Harville, Lakeland, Fla., assignors to W. R.Grace & C0., New York, N. Y., a corporation of Connecticut ApplicationJuly 13, 1953, SerialNo. 367,635

3 Claims. (Cl. 103-403) The present invention relates to centrifugalpumps and more particularly to a novel structure for dredge pumps.

Centrifugal pumps are of various designs, but always have a fixeddirection of discharge with respect to the Thus, except for small pumpswhich can operate in upside down position, one pump cannot serve todischarge to more than one direction. In certain mining operation, themined material is moved along by pumping it in an aqueous slurry. Thisis common practice in mining phosphate rock. In this typeof operation,the pumps must frequently be moved because of a shift in the miningoperations. At times it is desired to pump to the right or In order topump to different directions, it is necessary to have a separate pumpfor each direction. This means maintaining a large stock of pumps. Whenthe number of spare parts which must be carried to service these pumpsis considered, and the fact that the parts are not interchangeable, thedisadvantages of maintaining several pumps become apparent.

Furthermore, the casings of many types of pumps are split horizontally,vertically or diagonally. Because the split sections of conventionalpumps have irregular inner surfaces, it is diflicult to line them withspecial materials, such as abrasive-resistant liners.

By the present invention, there is now provided a pump which is adaptedto discharge in any desired direction tangential therewith and whoseinner surfaces are of regular contour so that lining is simplified.

It is, therefore, a principal object of this invention to provide a pumpthat can be used to discharge in any direction.

Another object of this invention is to provide a pump in which thedirection of discharge may be changed by simply reversing certain partsofthe pump.

Still another object is to provide a unitary, removable, .stutling boxfor pumps.

A further object is to provide a pump that has only flat or cylindricalinner surfaces.

A still further object of this invention is a novel method of attachingthe pump to a supporting base to secure the pump in place.

Other features of novelty will be apparent from the followingdescription taken in connection with the drawing.

Referring to the drawing:

Fig. 1 is a cross-section of the pump of the present invention.

Fig. 2 is a perspective view of the supporting base for the pump.

Fig. 3 is a perspective view of a pump and base.

Fig. 4 is a perspective view of a pump showing the shaft, the unitary,removable, stuffing box bolted in place, and the supporting base.

Fig. 5is a perspective view of a modification of the sup porting basefor the pump.

Referring now to Fig. 1, a flanged circumferential member 1 is disposedbetween side plates 2 and 3 which are joined by bolts 4 to form withsaid circumferential member a casing shown generally at 5.. For someuses, it is desirableito line the pump with an abrasion-resistingmaterial, as at 6, which may be rubber or any other abrasionresistingmaterial, depending upon the use to which the pump is intended. Sideplates 2 and 3 of the casing 5 have axial openings of equal diameter andcorresponding outwardly extending nozzles 7 and 8 having at their outerextremities, corresponding outwardly-directed flanges 7A and 8A. Animpeller 9 is mounted on shaft 10, which extends through one of saidnozzles into casing 5 and which is connected to an outside driving means(not shown). p

A unique feature of the present invention is the removable, unitarystufling box 11 which consists of innerand outer concentric sleeves 12and 13 secured to flange 14,

which, in turn, is attached to flange 7A of nozzle 7 by means of bolts15. The inner and outer sleeves 12 and 13 project inwardly from flange14 and, at their inner extremities, are secured to ring 16 to form anannular space 27. The inside diameter of the inner sleeve 12 is somewhatgreater than the diameter of the shaft 10 so that packing 17 can beinserted into the annular space between the shaft 19 and inner sleeve12. Ring 16 extends inwardly of sleeve 12 to form a flange therefor, asat 26. This flange 26 acts as a retaining ring for the packing 17, whichis urged inwardly by packing gland 18 which is secured to flange 14 bymeans of bolts 19. Inner sleeve 12 is perforated to permit the flow ofwater from the annular space 27 between sleeves 12 and 13 into thepacking 17, said water entering from an external source (not shown)through inlet 20. The water in space 27 prevents the entry of air aroundpacking 17 which would result in the loss of part or all of the pumpsuction. The water also acts as a cooling agent.

The unitary stuifing box may be attached to either of said flanges 7Aand 8A since each side plate is a mirror image of the other. When thestufling box is secured to the pump as in Fig. 1, nozzle 8 is used asthe pump intake.

The intended use of the pump may dictate a modification in the structureof the unitary stufling box.

To reverse the direction of discharge, bolts 15 are removed to permitwithdrawal of stulfing box 11 from nozzle 7, the pump sides areexchanged, the impeller is replaced by one of opposite hand, and themotor is reversed. Thus, stuffing box 11 is inserted, now, into nozzle 8and is bolted to flange 8A. Nozzle 7 now is employed as the intake ofthe pump.

Fig. 2 shows the supporting base for securing the pump 5 in place. Thecurved longitudinal metal rib 21 has bolt holes 22 and is weldedtransversely to metal base plates 23. The bolt holes 22 receive thebolts 4 of the pump to secure the pump 5 in a vertical position. Thesupporting base may be modified to include two longitudinal ribs 21a and21b as shown in Fig. 5, instead of one. When one longitudinal rib isused, spacing sleeves or collars (not shown) must be placed 'on thebolts 4 between said rib and the side plates 2 and 3 to prevent the pumpfrom riding along the bolts 4. Another variation in the structure of thesupporting base is to employ only one metal baseplate 23a as shown inFig. 5. In this instance the base plate would extend in length slightlybeyond the length of the rib. One or two ribs may be used with one baseplate.

Fig. 3 shows the pump completely assembled and mounted on the supportingbase. The material enters inlet 24 and is discharged through port 25.This figure shows the pump in position for a left-hand bottom dischargewith respect to intake. A right-hand top discharge may be formed bymerely removing the bolts 4 from the bolt holes 22 (not visible) of thesupporting base and turning the pump degrees on its base. The pump isthen bolted to a supporting base having holes corresponding to the'holes of the pump side plates at that position to secure the pump inplace. Similarly, the point of discharge may be altered to any degree byfollowing the aforesaid procedure.

- Fig. 4 is a reverse view of Fig. 3 and shows the pump secured to thesupporting base, having a single longitudinal rib 21. The describedcollars or sleeves not shown would be used on the bolts 4 to preventriding of the pump 5 on said bolts.

This pump is unique in that the side plates and openings and nozzles onthe side plates are identical but re,- so that the pump can be maderight or left-hand, top or be tom discharge, as previously described.The unitary stufling box is'a separate part of the pump and fits intothe side plate rather than being an integral part thereof.

- Another novel feature is the means of securing the pump. The pump issecured in place by a supporting fabricated from steel plate and drilledto match the bolt holes around the side plates of the pump. The boltswhich clamp the two side plates to the center member pass through theholes in the supporting base also. Because the pump is of a volutecontour, when the pump discharge is rotated to any of a number ofpossible angles it is necessary to substitute an alternate supportingbase which can be easily fabricated from steel plate. If the hand of thepump is changed from left to right or from right to left withoutchanging the angle of discharge the supporting 'base does not need to bereplaced.

A peculiar advantage of the pump construction is the use throughout ofparts, other than the pump impeller, which are fabricated from steelplate or steel tubing and assembled by Welding. Most such pumps areformed of cast iron, necessarily massive to prevent breakage and towithstand abrasion. The steel plate construction allows for much thinnerand lighter sections to be used. The nature of steel is such that ittends to flex rather than fracture under stress. Since anabrasion-resistant material is used to cover the steel sections wherethe pumped material contacts it the thick Wearing sectional areas ofcast iron pumps are not needed. Ease of repair is another factor ofimportance in economical pump operation. if a cast iron pump isfractured or burst from any cause it cannot be repaired in any practicalmanner. If a pump fabricated from steel plate and tubing, cracks or isaccidentally abraded the defective portions can be easily restored bywelding and the pump put back in service with a minimum of delay andexpense.

In addition to the previously listed advantages, the pump of the presentinvention has no irregular inside surfaces. For lining this pump, sheetmaterial can be easily cemented or otherwise applied thereto. Materials,such as a metal or metal alloy, or rubber can be employed to line theinner surfaces, depending upon the use for which the pump is intended.

In mining phosphate rock, great quantities of sand and rock are handledin a water-slurry in centrifugal pumps and pipe lines. The materialhandled is very abrasive and ordinary cast iron pumps wear out rapidly.Rubberdined pumps are available for handling fine sands, butmanufacturers are reluctant to recommend rubber lined pumps for handlingslurries containing large stones mixed with finer sands.

There are two ways of rubber lining a pump. One way is to mold areplaceable liner to fit loosely inside the pump casing. This has thedisadvantage that any sharp object caught in the pump will cut thelining to pieces. The other way to rubber line a pump is to cement orvulcanize sheet rubber to the inside of the pump. In conventional pumps,this must be done with thin sheets, since the lining must be made toconform to the irregular inner surfaces of the pump. An occasional sharpobject may scratch and score this sort of rubber lining, but it will notcut it to pieces. 3 A cemented rubber lining gives satisfactory serviceWhere the material handled is fine grained. When ell) large sized stonesare present, however, the impact of a single stone on the rubber liningmay be sufficient to cut through the rubber to the metal casing.Repeated pounding will soon beat the rubber lining off.

The design of our pump facilitates lining with rubber of any desiredthickness. The correct thickness of the lining depends upon thperipheral speed of the pump impeller, the size of the maximum sizedstone and the specific gravity of the slurry that will pass through thepump, and the resiliency of the rubber. In one installation, we havefound that one inch of rubber of average resiliency will withstand about600 foot-pounds of energy when the velocity of impact is about ft. persecond. Stones passing through the pump strike the rubber lining andbounce oif without damaging the rubber.

While this invention has been described in detail with respect to aparticular embodiment, it is not limited by the size or design or theapplication of the pump. The scope of the invention is indicated by theappended claims.

We claim:

1. A centrifugal pump comprising in combination paired identical fiatmetal side plates each having axial openings of equal diameter,corresponding nozzles of equal diameter extending outwardly from eachaxial opening, said nozzles having corresponding outwardly-directedflanges, a flanged circumferential member disposed between said sideplates and having a substantially smooth inner surface, means removablysecuring said side plates to said circumferential member in fixedassociation to form a casing having an axial intake and a tangentialdischarge, a shaft extending through one of said nozzles into saidcasing, an impeller mounted on said shaft and disposed within saidcasing, a unitary stufiing box housed Within one of said nozzlesdisposed around said shaft and removably secured to the flanged portionof said nozzle, and means adjustably supporting said pump.

2. The pump as defined in claim 1 wherein the inner surface of thecircumferential member is lined with an abrasion-resistant material.

3. A centrifugal pump comprising in combination paired identical fiatmetal side plates each having axial openings of equal diameter,corresponding nozzles of diameter equal to the diameter of the axialopenings and extending outwardly therefrom, said nozzles havingcorresponding outwardly-directed flanges, a flanged circumferentialmember disposed between said side plates and having a substantiallysmooth inner surface, means removably securing said side plates to theflanged portion of said circumferential member in fixed association toform a casing having an axial intake and a tangential discharge, aunitary stuffing box housed in the annular space between said shaft andthe wall-of said nozzle to form a seal, means removably securing saidstuifing box to said nozzle at its flange, and means adjustablysupporting said pump along the curvature of said casing.

References Cited in the file of this patent UNITED STATES PATENTS394,400 Sailor Dec. 11, 1888 860,465 Handcock et al. July 16, 19071,019,762 Cousans Mar. 12, 1912 1,081,725 Dodge et a1 Dec. 16, 19131,345,951 Phelps July 6, 1920 1,381,673 Sherwood June 14, 1921 1,471,559Knauf Oct. 23, 1923 1,515,816 Smith Nov. 18, 1924 1,639,779 MacPhersonAug. 23, 1927 1,805,765 Frederick May 19, 1931 1,873,386 GoldthwaiteAug. 23, 1932 1,881,723 Lee Oct. 11, 1932 1,909,095 Cofiln May 16, 19331,990,519 Bigelow et al. Feb. 12, 1935 2,232,648 Allen Feb. 18, 19412,624,599 Eaton Jan. 6, 1953

